Evaluating the Performance of Transformer Insulation Materials Using Finite Element Method

Abstract

Power transformers proper working is highly dependent on the health of its insulation. With usage the performance of the oil-paper insulation used in transformer gets degraded due to many factors namely the various electrical, thermal and mechanical stresses acting on the insulation. Partial discharges are found to be the main cause of the insulation degradation. The inter-relationship between electric field distribution and discharge patterns are useful in characterising the mechanism of streamer formation and thus optimise the discharge activity in the insulation. Here two models are considered to see how the field distribution assists in discharge formation by using two variants of insulating oil and thus evaluating their performance with aging. Online studies provides a way for continuously monitoring the development of discharges that degrades the performance of insulation thus accelerating its aging.